FIG. 1 illustrates an example of electric signal output equipment available in the prior art and which is employable for reading a plurality of binary signals out of a memory and for outputting the signals to a computer or the like, after such binary signals are converted to ON-OFF signals. Referring to FIG. 1, numerals 1, 2 and 5m respectively indicate a control circuit, a memory and a plurality of latches. The plurality of latches 5m are grouped or divided into m groups. Only 3 groups are illustrated in FIG. 1. Each group of the latches 5m has n elements, although only 4 elements are illustrated for each group. Numeral 6mn indicates a plurality of output driver circuits. These driver circuits 6mn are also grouped into m groups (only 3 groups are illustrated in the drawing), and each group of the output driver circuits 6mn is connected with the corresponding group of the latches 5m, which group has n elements (only 4 elements are illustrated in the drawing). Numeral 4mn indicates a plurality of displays, of which the total quantity equals to the product of "m" and "n". They are also grouped into m groups (only 3 groups are illustrated in the drawing), and each group of the displays 4mn is connected with the corresponding group of the latches 5m, which group has n elements. Each group of the displays 4mn is also connected with the corresponding group of the driver circuits 6mn, which group has n elements.
In the aforementioned electric signal output equipment available in the prior art, binary signals are consecutively read out of the memory 2 into the designated address of the latches 5m, in response to a group of commands (The combination of a group of address commands A and a read-out command R) issued by the control circuit 1. Since a latch has a static nature or holds a signal until another signal is applied and replaces the former signal, the designated address of the latches 5m continuously outputs the signal latched therein to a computer or the like (not shown) through the corresponding one of the driver circuits 6mn. Incidentally, the designated address of the latches 5m causes the corresponding one of the displays 4mn to continuously work, during the period in which the designated address of the latches 5m holds a signal.
The aforementioned electric signal output equipment available in the prior art is designed to allow each address of the latches 5m to operate cyclically. In other words the latest signals are applied to a computer or the like virtually on an on-line basis and the ON-OFF position of the signals which are currently being applied to the computer or the like are displayed on the corresponding displays. Thus, the signals are displayed during the period in which such signals are being applied to the computer or the like. However, the necessary quantity of the latches 5m, the driver circuits 6mn and the displays 4mn equals "mxn" or the product of the quantity "n" of the elements included in each group of the latches etc. and the quantity "m" of the groups of the latches etc., which equal to the total quantity of the output circuits. This causes a drawback in which the necessary quantity of the elements of the latches 5m becomes identical to that of the output circuits, resultantly requiring a large space and large amount of production cost.